#include "simpleViewer.h"

using namespace std;

// Draws a spiral
void Viewer::draw()
{
  const float nbSteps = 200.0;

  glBegin(GL_QUAD_STRIP);
  for (int i=0; i<nbSteps; ++i)
	{
	  const float ratio = i/nbSteps;
	  const float angle = 21.0*ratio;
	  const float c = cos(angle);
	  const float s = sin(angle);
	  const float r1 = 1.0 - 0.8f*ratio;
	  const float r2 = 0.8f - 0.8f*ratio;
	  const float alt = ratio - 0.5f;
	  const float nor = 0.5f;
	  const float up = sqrt(1.0-nor*nor);
	  glColor3f(1.0-ratio, 0.2f , ratio);
	  glNormal3f(nor*c, up, nor*s);
	  glVertex3f(r1*c, alt, r1*s);
	  glVertex3f(r2*c, alt+0.05f, r2*s);
	}
  glEnd();
}

void Viewer::init()
{
  // Restore previous viewer state.
  restoreStateFromFile();

  // Opens help window
  help();
}

QString Viewer::helpString() const
{
  QString text("<h2>S i m p l e V i e w e r</h2>");
  text += "Use the mouse to move the camera around the object. ";
  text += "You can respectively revolve around, zoom and translate with the three mouse buttons. ";
  text += "Left and middle buttons pressed together rotate around the camera view direction axis<br><br>";
  text += "Pressing <b>Alt</b> and one of the function keys (<b>F1</b>..<b>F12</b>) defines a camera keyFrame. ";
  text += "Simply press the function key again to restore it. Several keyFrames define a ";
  text += "camera path. Paths are saved when you quit the application and restored at next start.<br><br>";
  text += "Press <b>F</b> to display the frame rate, <b>A</b> for the world axis, ";
  text += "<b>Alt+Return</b> for full screen mode and <b>Control+S</b> to save a snapshot. ";
  text += "See the <b>Keyboard</b> tab in this window for a complete shortcut list.<br><br>";
  text += "Double clicks automates single click actions: A left button double click aligns the closer axis with the camera (if close enough). ";
  text += "A middle button double click fits the zoom of the camera and the right button re-centers the scene.<br><br>";
  text += "A left button double click while holding right button pressed defines the camera <i>Revolve Around Point</i>. ";
  text += "See the <b>Mouse</b> tab and the documentation web pages for details.<br><br>";
  text += "Press <b>Escape</b> to exit the viewer.";
  return text;
}
